Pre-treatment of Pitching Yeast With Zinc

By Behnam Taidi, B. Hoogenberg, A. I. Kennedy and J. A. Hodgson Scottish Courage Brewing Ltd., Canongate, Edinburgh, Scotland, United Kingdom. Poster presented at the World Brewing Congress 2000, Orlando, Florida, USA.

Abstract
Preconditioning of yeast with zinc during acid washing was a way of overcoming zinc deficiency in wort provided that the barm beer was not separated prior to pitch. This is because uptake of zinc by the yeast was not efficient during the acid washing process. The optimum point of zinc supplementation was directly to wort at the exact time of pitching. Zinc addition to hot wort can result in a decrease in the bioavailable zinc concentration in wort and poor fermentation.
Keywords: yeast washing, zinc acid washing  

Sintesis
El preacondicionamiento de la levadura con zinc durante el lava-do con �cido era una manera de sobrepasar la deficiencia de zinc en el mosto mientras que la levadura de la cerveza no fuera separada antes del tirado. Esto es porque la combinaci�n del zinc con la levadura no era eficiente durante el proceso de lavado con �cido. El punto de �ptimo del suplemento del zinc era directamente al mosto al momento exacto del tirado. La adici�n de zinc al mosto caliente puede resultar en la disminuci�n de la concentraci�n del zinc biodisponible en el mosto y en fermentaci�n pobre.